US4476217A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sensitive positive electron beam resists
Assignee: Honeywell Inc
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Filing: 1984-02-13
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Granted: 1984-10-09
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Expires: 2004-02-13
Abstract
Abstract Highly sensitive positive electron beam resists comprised of copolymers of methacrylic acid (MAA) and t-butyl methacrylate (TBM) are disclosed in which a thin film of high molecular weight MAA/TBM copolymer is applied to a suitable substrate. Prior to exposure, the copolymer is prebaked at a temperature below the decomposition temperature to improve the sensitivity and resolution of the resist. The exposed resist is developed by spraying with a suitable solvent. The positive electron resists produced in accordance with the present invention exhibit a high sensitivity and good submicron resolution.
Inventors
- 👤 Richard B. Douglas
- 👤 Barbara J. Fure
- 👤 Juey H. Lai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:01
CPC Classifications
B; B05; B05D; B05D3/00; B05D3/10; G; G03; G03F; G03F7/00; G03F7/004; G03F7/039
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
119 words
A method of producing a sensitive positive radiation sensitive resist image comprising the steps of: obtaining a solution of a radiation sensitive copolymer material comprising from about 55 to 80 mole percent methacrylic acid (MAA) and from about 20 to 45 mole percent t-butyl methacrylate (TBM), wherein the weight average molecular weight of the copolymer is equal to or greater than 250,000, coating a substrate with the solution of MAA/TBM copolymer to form a thin polymeric film of said polymeric material thereon; prebaking the coated substrate at a temperature equal to or greater than 200° but below the decomposition temperature of said polymer material; exposing said polymeric film to ionizing radiation in a predetermined pattern; developing said polymeric film.
Claim 2
Independent Claim
119 words
A method of producing a sensitive positive radiation sensitive resist image comprising the steps of: obtaining a solution of a radiation sensitive copolymer material comprising from about 55 to 80 mole percent methacrylic acid (MAA) and from about 20 to 45 mole percent t-butyl methacrylate (TBM), wherein the weight average molecular weight of the copolymer is equal to or greater than 250,000, coating a substrate with the solution of MAA/TBM copolymer to form a thin polymeric film of said polymeric material thereon; prebaking the coated substrate at a temperature equal to or greater than 200° but below the decomposition temperature of said polymer material; exposing said polymeric film to ionizing radiation in a predetermined pattern; developing said polymeric film.
Claim 3
Dependent Claim
25 words
The method according to claim 1, wherein said prebaking step is carried out at said prebaking temperature from about 20 minutes to about 2 hours.
Claim 4
Independent Claim
40 words
The method according to any of claims 1 wherein said developing step further comprises spraying said exposed polymeric film on said substrate with a liquid solvent for said resist for a period of from about 10 seconds to 60 seconds.
Claim 5
Dependent Claim
33 words
The method according to claim 3 wherein said solvent is one selected from the group consisting of methyl cellosolve, methyl isobutyl ketone, isopropanol, cellosolve acetate, methyl ethyl ketone and ethanol or combinations thereof.
Claim 6
Dependent Claim
40 words
The method according to claim 4 wherein said developing step further comprises spraying said exposed polymeric film on said substrate with a liquid solvent comprising a mixture of methyl cellosolve and methyl isobutyl ketone have a ratio of approximately 1:1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-09 | 1988-04-09 | 1988-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-09 | 1992-04-09 | 1992-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-09 | 1996-04-09 | 1996-10-09 | $7700.00 | Window Closed / Lapsed |